XO1.75 B1 C1 Changes
This page is monitored by the OLPC team.
These are the changes planned for the XO-1.75 C1 prototype, from the B1 prototypes.
Contents
C1 Electrical Fixes
Improved MPPT
The circuit generating the PWR_LIMIT_ON needs to be modified to only assert the signal if power limiting is turned on. On B1, it is asserted whenever the laptop is accepting power from the DC input (power limited or not).
The LV_SET signal should probably change to a EC PWM output, allowing a greater voltage swing than the EC DAC output.
Modify Vcore supply
The Vcore suply voltages should be 1.345V nominal and 1.25V nominal, instead of 1.40V and 1.345V as it is now.
